Drilling, completion operations and production operations for oil and gas often creates millions of gallons of wastewater. This wastewater is often pumped into a reservoir. The wastewater must be removed for continuous operations or regulatory zero discharge requirements. Off-site disposal and trucking the wastewater is costly. Natural evaporation is slow and inefficient. What is needed is a cost efficient way to remove large quantities of wastewater with as minimal environmental impact as possible.
U.S. Pat. No. 4,449,849 (1984) to Horm et al. discloses oil drilling wastewater evaporator using a land based pump to spray via nozzles the water all around the edge of the reservoir back into the reservoir. A float can support a splashplate to increase the rate of evaporation from the land based nozzle.
U.S. Pat. No. 7,448,600 provides a floating device that supports over a dozen high speed atomizing fans. The floating device is tethered from the sides of the reservoir or anchored in the reservoir. Power (preferably hydraulic) is supplied from a land based power unit. Hydraulic fluid, once cycled for power to the fans and the water pump, is used to pre-heat the water, thereby adding efficiency to the entire system. This hydraulic fluid also is used to transport the land based engine cooling heat out to the unit. Another heat exchanger on the land based power unit removes the heat from the coolant and adds it to the oil coming back from the return lines before it goes to the storage tank. All the components can be mounted on a custom trailer to enable portability among several sites.
Problems with this system include the top heavy buoyancy of a raft confined to the width of a trailer. Another problem is the uncontrollable direction of the evaporative cloud which can contaminate nearby equipment. Also no droplet size control exists for varying humidity and wind conditions.
The present invention solves these and other problems with a collapsible raft that widens to a large stance in the water. A plurality of environmental sensors are monitored by a control computer and optionally this data can be transmitted in real time to a remote control headquarters.